package com.anmong.cloud.cloudcommon.util;

import lombok.extern.slf4j.Slf4j;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.URL;
import java.net.URLConnection;
import java.util.List;
import java.util.Map;

@Slf4j
public class HttpUtil {

    /**
     * 向指定URL发送GET方法的请求
     *
     * @param url
     *            发送请求的URL
     * @param param
     *            请求参数
     * @return URL 所代表远程资源的响应结果
     */
    public static String sendGet(String url, Map<String,Object> param) {
        String result = "";
        BufferedReader in = null;
        try {
            String urlNameString = url;

            //增加参数
            if(param!=null&&param.size()>0){
                urlNameString = urlNameString+"?";
                for(String key : param.keySet()){
                    urlNameString = urlNameString + key + "=" + param.get(key) + "&";
                }
                urlNameString = urlNameString.substring(0,urlNameString.length() -1);
            }
            URL realUrl = new URL(urlNameString);
            // 打开和URL之间的连接
            URLConnection connection = realUrl.openConnection();
            // 设置通用的请求属性
            connection.setRequestProperty("accept", "*/*");
            connection.setRequestProperty("connection", "Keep-Alive");
            connection.setRequestProperty("user-agent",
                    "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");
            // 建立实际的连接
            connection.connect();
            // 获取所有响应头字段
       /*     Map<String, List<String>> map = connection.getHeaderFields();
            // 遍历所有的响应头字段
            for (String key : map.keySet()) {
                System.out.println(key + "--->" + map.get(key));
            }*/
            // 定义 BufferedReader输入流来读取URL的响应
            in = new BufferedReader(new InputStreamReader(
                    connection.getInputStream()));
            String line;
            while ((line = in.readLine()) != null) {
                result += line;
            }
        } catch (Exception e) {
            log.error("发送 GET 请求出现异常！",e);
        }
        // 使用finally块来关闭输入流
        finally {
            try {
                if (in != null) {
                    in.close();
                }
            } catch (Exception e2) {
                log.error("发送 GET 请求出现异常！",e2);
            }
        }
        return result;
    }
}
